Improvement in solutions for preserving canvas and cordage



ITNITED STATES FFICE.

PATENT OHRES'IEN NELSON, OF GLOUCESTER, MASSACHUSETTS.

Specification forming part of Letters Patent No. 134,559, dated January 7, 1873.

To all whom it may concern:

Be it known that I, GHREsrEN NnLsoN, of Gloucester, in the county of Essex and State ofMassachusetts, have invented a'certain Improved Solution for Preserving Canvas and Cordage, of which the following is a specification:

The object of this invention is to provide a means of protecting canvas tent-cloth, sails, and Manila cordage from mold and rapid decay when exposed in damp places.

In the compounds at present employed for this purpose the active ingredients or antiseptic agents are used in an acid or nearly neutral condition, and although they afford partial protection against mildew, they do,not fully preserve canvas and cordage in warm climates, as they apparently weaken the fabric by their corrosive or acid action" upon it. But I have discovered that an alkaline solution ot'zinc (which, being nearly colorless, does not impart an objectionable color to canvas) is a much more efficient protector than any of the compounds previously used.

To enable others skilled in the art to make use of my invention, I will now recite my formula and mode of procedure, as follows I dissolve one pound of sulphate of zinc in a tank or tub containing forty gallons of water, and then add one poundof sal soda or three quarters of a pound of soda-ash. After-stirring, to insure complete solution of these ingredients, I then add, with further stirring, two ounces of tartaric acid, which serves to hold the partially separated carbonate of zinc in solution without neutralizing the excess of alkali used. I soak the canvas or cordage in this solution for twenty-four hours, then remove and dry it in the sun and open air or by artificial heat, Without wringing or removing the excess of solution from the fabric.

I do not confine myself to the exact proportions of ingredients given above,but it is es sential that there should be a considerable excess of the alkali present.

Having thus described myinvention, I claim as new and desire to secure by Letters Patent The improved solution for preserving canvas and cordage prepared and used as herein set forth.

GHRESTEN NELSON.

Witnesses:

EBEN PAGE, CYRUS STORY. 

